This is a lump of labor fallacy.

By finding a ready source of people willing to staff the water park at a lower price, more ‘water park amenity’ is available at a lower price.

This frees up the labor of local teenagers who can now be employed in other roles, producing other useful things for society, like… I don’t know what teenagers do nowadays. Provide market-clearing services on Kalshi by placing bad bets? Upload short form video to TikTok to enable ad buyers to find customers?